Vehicle wheel

ABSTRACT

A wheel for vehicles is comprised of a rigid circular inner wheel which is surrounded by a continuous flexible track having a plurality of pad elements joined together continuously in edgeto-edge relationship by a plurality of hinge means, each of which is interposed between the adjacent edges of the pad elements. A plurality of arcuate members each have a first end pivotally connected to one of the hinge means and a second end pivotally connected to another of the hinge means. The arcuate members span at least two pad members. Each of the hinge means is pivotally connected to at least one of the first ends of the arcuate members so that the arcuate members overlap one another, and a plurality of crank elements are each connected at one of their ends to one of the arcuate members and at the other of their ends to the inner wheel. A lubrication system is also provided for the crank members so as to facilitate lubrication of the pivotal joints at the opposite ends of the crank members.

United States Patent [1 1 Reisser [11] 3,779,616 [451 Dec. 18, 1973 I VEHICLE WHEEL [76] Inventor: Vernon H. Reisser, 10607 Poppleton Ave., Omaha, Nebr. 68124 22 Filed: Sept. 23, 1971 21 App1.No.: 183,085

[52] US. Cl. 305/19 [51] Int. Cl B6211 55/08 [58] Field of Search 305/3, 19

[56] References Cited UNITED STATES PATENTS 2,418,481 4/1947 Riblet 305/19 1,220,852 3/1917 Johnson 305/3 FOREIGN PATENTS OR APPLICATIONS 338,350 11/1930 Great Britain 305/19 Primary ExaminerRichard J. Johnson Attorney-Zarley, McKee and Thomte 5 7] ABSTRACT A wheel for vehicles is comprised of a rigid circular inner wheel which is surrounded by a continuous flexible track having a plurality of pad elements joined together continuously in edge-to-edge relationship by a plurality of hinge means, each of which is interposed between the adjacent edges of the pad elements. A plurality of arcuate members each have a first end pivotally connected to one of the hinge means and a second end pivotally connected to another of the hinge means. The arcuate members span at least two pad members. Each of the hinge means is pivotally connected to at least one of the first ends of the arcuate members so that the arcuate members overlap one another, and a plurality of crank elements are each connected at one of their ends to one of the arcuate members and at the other of their ends to the inner wheel. A lubrication system is also provided for the crank members so as to facilitate lubrication of the pivotal joints at the opposite ends of the crank members.

35 Claims, 13 Drawing Figures airframe PAIENIED on: 18 ms SHEEI :10; 3

2 W W W 2 m h M firm/ways VEHICLE WHEEL This invention relates to vehicle wheels.

One disadvantage of a circular wheel is the fact that only a small portion of its outer perimeter engages the ground. Collapsible, or partially collapsible wheels have been constructed to increase the surface which engages the ground. For example, a common rubber tire is partially collapsible and includes a small flat surface which engages the ground. Most of these devices have been circular in construction, and as a result of this circular configuration they minimize the surface which can engage the surface of the ground. Elliptical tracks have been provided such as found on bulldozers, but these tracks require two wheels around which the tracks are trained.

Therefore a primary object of the present invention is the provision of a wheel which is elliptical in shape and which is driven by a singular circular inner wheel.

A further object of the present invention is the provision of a wheel which transforms circular or elliptical movement of its outer surface above the terrain to substantially linear movement at the point where its outer surface engages the terrain.

A further object of the present invention is the provision of a wheel which includes a substantially elliptical track having a major axis parallel to the general contour of the terrain and which maintains that parallel relationship during movement of the track around the rotational axis of the wheel.

A further object of the present invention is the provision of a wheel which will maintain a substantially elliptical shape with the major axis approximately parallel to the general terrain even when the vehicle is moving over rough terrain or large rocks.

A further object of the present invention is the provision of a wheel which includes means for transferring a load force concentrated at one point on its track perimeter substantially around the entire track.

A further object of the present invention is the provision of a wheel which includes an enclosed lubricating system for lubricating the moving parts of the track without exposing them to the elements and dirt on the ground.

A further object of the present invention is the provision of a wheel having an inner wheel and an outer track rotating in the same direction at constant speeds and having a plurality of cranks pivotally interconnecting the inner wheel and the track and rotating at a constantly varying speed in a direction opposite from the rotation of the inner wheel and the track.

A further objective of the present invention is the provision for a wheel whose radius is constantly increasing and decreasing while maintaining a near constant form, and whose structural components maintain their structural form without structural strain when laterally stressed.

A further object is the arrangement in the assembly of rotating component parts in their cycle of rotation which reduces initial impact loads between track and terrain.

A further object of this invention is to increase the safe working speeds of track vehicles and to be able to interchange pneumatic tired wheels with flexible track type wheels, on wheel type vehicles.

A further object of the present invention is the provision of a wheel which is economical to manufacture, durable in use and efficient in operation.

These and other objects will be apparent to those skilled in the art.

This invention consists in the construction, arrangements and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in the claims, and illustrated in the accompanying drawings in which:

FIG. 1 is a perspective view of a tractor utilitizing the wheel of the present invention.

FIGS. 2 4 are plan views of the tractor of FIG. 1 illustrating the position of the wheel as the tractor passes over a rock or other object.

FIG. 5 is a fragmentary plan view of a portion of the track illustrating the arcuate members which interconnect the pads of the track.

FIG. 6 is a sectional view taken along line 6 6 of FIG. 5.

FIG. 7 is a fragmentary perspective view of the valve and plug which are mounted in the lubricant reservoir.

FIG. 8 is a sectional view taken along line 8 8 of FIG. 7.

FIG. 9 is a partial sectional view illustrating the relative positions of the crank elements, the arcuate legs, and the track pad elements of the present invention.

FIG. 10 is an exploded perspective view of illustrating the structure of one of the track sections of the wheel of the present invention.

FIG. 11 is a view similar to that in FIG. 9, but showing a modified form of the invention.

FIG. 12 is a sectional view taken along line 12 12 of FIG. 11.

FIG. 13 is a sectional view taken along line 13 13 of FIG. 11.

Referring to the drawings, a tractor 10 is illustrated having a pair of vehicle wheels 12 thereon which embody the structure of the present invention. Wheels 12 each include a hub 14 to which is welded a circular inner wheel 16. Referring to FIG. 6, inner wheel 16 in cludes a pair of spaced apart annular flanges 18 20 which lie in a vertical plane and which are interconnected by a circular annular web 22 which is perpendicular to flanges l8 and 20. Flange 20 is welded to annular web 22, but flange 18 is bolted to web 22 by a bolt 24 so as to permit removal of flange 18 from web 22. Surrounding inner wheel 16 in outward radial spaced relationship thereto is an elliptically shaped track 26 which is comprised of a plurality of pad elements pivotally joined together in edge-to-edge relationship. Each pad element includes a first edge 30 (FIGS. 5, 9 and 10) having a pair of closely spaced bushings 32 mounted thereon. Each pad element also includes a second edge 34 opposite fromfirst edge 30 and having a pair of widely spaced bushings 36 mounted thereon. Pads 28 are positioned so that widespaced bushings 36 of one pad 28 are in registered alignment with closely spaced bushings 32 of the adjacent pad 28. A hinge shaft 38 extends through each of the aligned bushings 32, 36 so as to provide a hinged connection between each of the adjacent edges of pads 28.

A plurality of arcuate members 40 each include a pair of arcuate legs 42, 44 which are joined at a V- shaped end 46 and which diverge therefrom to form a pair of divergent ends 48. A center bushing 50 is provided at V-shaped end 46 and a pair of widely spaced bushings 52 are provided at divergent ends 48. Bushing 50 is adapted to be aligned between closely spaced bushings 32; and bushings 52 are adapted to be aligned between the ends of bushing 32 and spaced bushings 36, so as to be rotatably mounted on hinge shaft 38. As can be seen in FIGS. 9 and 10, arcuate members 40 are sized to span two pad elements 28 and to be pivotally connected to shaft 38 at the opposite outer edges of the two pad elements 28. Also, as can be seen clearly in FIGS. and 9, each shaft 38 is adapted to provide a pivot bushing 50 for one center V-shape divergent end 46 of one arcuate member 40 and two widely spaced divergent ends 48 supported by bushing 50 of a second adjoining arcuate member. Thus each shaft 38 supports adjoining arcuate members 40 and adjoining pad elements 28 both centrally and in opposite lateral direction across the face of the track. The distance between ends 46, 48 of arcuate members 40 is such that arcuate members 40 are horizontally unstressed when the two pad elements 28 therebetween form an angle of approximately 180 degrees. However, when pad elements 28 are pivoted so that they do not form an angle of 180 this shortens the distance between the two shafts 38 at the outer edge of the two elements 28 and thereby subjects arcuate member 40 to a bending force or stress.

Referring to FIGS. 6 and 10, an elongated bushing 54 is welded to arcuate member 40 at approximately the mid-point thereof and at a point equidistant from ends 46, 48 of each arcuate member 40. Rotatably journaled in the opposite ends of elongated bushing 54 are a pair of crank elements 56. Each crank element 56 includes a first shaft 58 which is rotatably journaled within bushing 54, an angled crank body 60, and a second shaft 62 adapted to be rotatably journaled within a bearing 63 carried by annular flanges l8 and 20. Thus, crank elements 56 pivotally interconnect arcuate members 40 to inner wheel 16.

Each arcuate member 40 has three triangular spaced support bushings at its base; two of which are aligned and one of which is parallel to the other two. Widely spaced bushings 52 and centrally positioned bushing 50 are parallel to elongated bushing 54 of arcuate member 40. Thus the triangular spaced bushings 48 and 50 of each arcuate member 40 establishes a perpendicular traingular rotatable working plane about the pivotal axis of elongated bushing 54. Elongated bushing 54 is rotatable about the first pivotal axis of the crank (axis of bushing 54) which is parallel and rotatable about the second pivotal axis of the crank (axis of shaft 62) of each crank assembly 56. The second pivotal axis of the crank is aligned on opposite sides with carrier bushing 63 supported by flange l8 and of the inner wheel 16.

The above described structure is preferred when maximum lateral stability is required, either when heavy vehicles are working on side slopes or when heavy wheel loads are carried on the right or left side of the track.

It should be noted that right and left crank elements 56 may be joined by a common shaft 58.

For purposes of reference, the pivot point about each of shafts 38 are labeled individually as A, B, C, D, E, F, G, H and I, respectively. The pivotal connection about shafts 58 are designated by the letters J, K, L, M, N, O, P, Q and R, respectively. FIGS. 1 4 show the elliptical track wheel whose cranks extend radially outward on the major axis through the center of hub 14 and whose cranks extend radially inward on the minor axis. FIG. 9 shows an expanded elliptical track wheel whose horizontal major axis is below the center of hub 14 and whose minor vertical axis passes through the center of hub 14. The cranks 56 which are located at points P, Q and R extend radially outwardly from their pivot connections of the inner wheel 16 below the major axis and the cranks 56 which are adjacent points J, K and L extend radially inwardly from their pivotal connections with inner wheel 16 on the minor axis.

Elliptical form, FIGS. 1 4, is substantially symmetric with the major axis and minor axis passing through the center of the hub 14. When cord length, between crank pivots 62, and crank length are constructed equal, the inner wheel crank pivot diameter 62 can be slightly increased to resolve a form as shown in FIG. 9. Then the major diameter remains perpendicular to the minor diameter but below the center of the inner wheel. This expanded elliptical wheel form will then resolve into a near cardioid shape with a longer flat base to carry the vehicles weight upon the terrain.

In FIG. 9 it is important to note that crank pivots L, K and J are substantially in a straight line perpendicular to the minor axis which resolves in a substantially flat track base with or without the force of the vehicles weight upon the wheel.

To resolve the form of the elliptical wheel the dimensional relation-ship of the following component parts, each with one another, is important:

1. Inner wheel crank pivot radius. (This is the distance from the center of the inner wheel to crank pivot 62.)

2. Crank radius (distance between shaft 62 and K FIG. 9).

3. Track width (distance between axis A and B).

4. Leg height (distance between axis B and K).

When a crank 56 is aligned with the minor axis FIG. 9, crank pivots J, K and L are substantially aligned and perpendicular to the minor axis and distance J K and L K is substantially equal and parallel to track pad width A B and C B. In FIGS. 1 9 crank length and cord length were intentionally made substantially equal. It was learned from other working models whose cord length and crank length were not substantially equal that closer interrelated tolerances must be maintained, for either elliptical shape FIG. 1 4 or as shown in FIG. 9. Likewise, with a greater number of crank, leg and track components, distance between crank ends 0 P (FIG. 9) are closer together where the radius of the track assembly is the smallest. When traveling over boulders, as shown in FIGS. 2, 3 and 4, there is an advantage in limiting crank distance 0 P which in turn limits the smallest radius a track assembly will form. In FIG. 9 when legs 40 are in contact at X and Y, the radius of the track is limited, or when a greater number of crank and leg assemblies make up an elliptical wheel, arcuate members 40 may mechanically limit distance P 0 between bushing 58 and legs 42 and 44 without effecting smooth continuous rotation. Thus arcuate members and crank assemblies may be constructed in a form other than is shown in FIG. 9. With reference to FIG. 9, with or without substantially equal crank and cord lengths, the geometric interrelationship of the various parts is shown.

Where the wheel radius is the greatest on or below the major axis and where the wheel rolling radius is the smallest on the minor axis, the radial stress upon component parts of the track to the center of hub 14 is the greatest, thereby forcing the elliptical track radially outward at crank pivots P, Q and R to its greatest wheel radius and pulling the track radially inward at crank pivots J, K and L to be at its minimum height on its minor axis and the smallest wheel radius. Likewise, the least radial stress of arcuate members 40 at crank piv ots G, H and I occurs in this cycle of rotation because crank assemblies 0, M and N are approaching, are on, or have passed over center. In this example center is when crank end 58 passed over inner wheel crank pivot 62. Each crank 58 passes over center in each of the four quadrants between the major and minor axis dur' ing one revolution of the elliptical wheel. Under this relationship an arc B, having its center at point B, passes through points J and L of the arcuate members 410 which are pivotally connected at point B. Similarly, an arc C, having its center at point C, passes through points vK and M which are found on the arcuate members 40 which are pivotally connected points C. Similar arcs D, E, F, G, H and I may be found for points D, E, F, G, H and I, respectively, and for all remaining crank and leg and track assemblies of the elliptical wheel. Thus, for each shaft 38, the pivotal connections between the crank members and the two arcuate members 40 connected to that shaft 38 are always located equidistant from shaft 38 within the tolerance of the slight flexing of the legs of the arcuate assembly 40. If the height B K of arcuate members 40 laying on the minor wheel axis is chosen such that the previously stated relationship exists for both equal and unequal crank and cord lengths, the track 26 will always have a near elliptical shape as shown in FIGS. 1, 2, 3 and 4 or an expanded elliptical shape described previously as a cardioid form with a flat bottom, as shown in FIG. 9, when the cranks second pivot axis of the inner wheel is slightly increased.

It should be noted in FIG. 9 that only one annular flange may be positioned around the center of the hub of inner wheel 16, with cranks 56 and arcuate members 40 on either side of annular flange 20 without changing the intent of the invention. Then leg ends 42 and 44-of arcuate members 40 would not necessarily be attached to a single bushing 50, FIG. 9.

In operation the inner wheel 16 and shaft 38 connecting track 26and arcuate members 40 will rotate in the same direction at a constant velocity. In FIG. 9 this direction is shown to be a counterclockwise direction, as

indicated by arrows 65. Crank elements 56, on the other hand, rotate in the opposite direction (clockwise, as viewed in FIG. 9) and are constantly varying their velocit-y throughout each revolution of inner wheel 16, arcuate members 40 and track 26. The variation in velocity, (acceleration and de-acceleration) of crank elesmallest on the minor axis, the distance between crank elements is the farthest apart. Thus the acceleration and de-acceleration of cranks J, K, L, M, N, O, P, Q, R and S is directly proportional to the decreasing and increasing distances between J, K, L, M, N, O, P, Q, R and S as measured by the lengths of arcs A, B, C, D, E, F, G, H, I, etc. Thus the acceleration and deacceleration of crank elements 56 is inversely proportional to the variation in the elliptical wheel radius. For each revolution of inner wheel 16, arcuate members 40 and inner wheel 16, elements 56 will rotate a complete revolution in the opposite direction.

The limited flexibility of arcuate members 40, both radially and horizontally, and the overlapping relationship which they have with respect to one another causes load forces applied to track 26 to be transmitted and spread around the circumference of track 26.

In FIG. 9 each arcuate member 40 maintains a three point space relationship about two shafts 38 and one crank pivot 58 which is substantially perpendicular to an intermediate track shaft 38 supporting two adjoining arcuate members 40 and two pad elements 28. The two adjoining arcuate members 40 each have their respective three point space relationship (described above) with their respective crank pivots 58 and shafts 38. Likewise each crank 56, rotating about crank pivot 62 in its cycle of rotation, has its space relationship between adjacent crank pivot 58 supporting arcuate members 40 within the arc of crank rotation about shaft 62. Shafts 62 are equally spaced around and near the perimeter of the inner wheel 16. Both shafts 58 and track shafts 33 maintain a substantially elliptical rotat' ing form when track shafts 38 are pivotally connected to a continuous flexible track, because pads 28 maintain equal space relationship between shafts 38.

It is the continuous rotation of all component parts operatively connected to the'inner wheel which resolve in an elliptical form that is of prime importance in this invention. The primary geometric function of track pads 28 is to maintain an equal space relationship between shafts 38 in order to maintain an elliptical continuous rotating form. Thus flexible track pads 28 may also be in the form of a continuous flexible heavy rubber belt when the flexible rubber belt maintains equal or very near equal space relationship between shafts 38.

Referring to FIG. 9, when track 26 encounters a rock 64, the weight of the vehicle plus the centrifugal force of the rotating track mass is opposed by radial inward forces at the point where rock 64 engages track 26. Arrows 65A demonstrate the distribution of this load force throughout the members of track 26. These load forces are transmitted through the two arcuate members 40 at the point of contact E and are additionally transmitted through pad elements 28 adjacent to the point of contact. Thus the relative crank rotating position at O and M determines the relative crank rotating position of P, N and L. In a chain reaction the relative rotating crank positions of crank pivots P, O, N, M and L determine the relative rotating position of all remaining cranks of the flexible track wheel.

It is the object in construction to reduce the initial impact loads upon the face of the track where the track first makes contact with the terrain, and thereby increase working speeds of a track vehicle. It is important to note that the direction of the initial impact force is in the direction of rotation of cranks M and O. Cranks P, N and L are also rotating clockwise in the direction of the external forces with or without rock 64. In FIG. 9, as point E begins to yield in the direction of the impact loads over rock 64, cranks O and M slightly change their rate of acceleration in the direction of crank rotation. Likewise, crank pivot N, P and Q slightly change their respective accelerated position in the direction of crank rotation to raise the elliptical wheel over rock 64. A chain reaction of implied forces upon all crank, arcuate and flexible track members around inner wheel 14 raises and lowers the vehicle over rock 64 in a resilient manner as shown in FIGS. 2, 3 and 4. Reducing the initial impact loads between the face of the flexible track and a hard surface road is very important when elliptical track wheels replace pneumatic tires on high speed vehicles.

It is important to note that the majority of torque from the inner wheel to the outer surface of the track is transferred in the cycle of crank rotation between crank position to L as shown in FIG. 9 and by equal crank positions on the opposite side of the minor axis (not shown). When the direction of travel is as shown, the counterclockwise rotation of the inner wheel is pulling crank elements 56 at O, N, M and L and their respective arcuate members 40 and track 28 in the direction of inner wheel rotation while equal crank positions on the opposite side of the minor axis (not shown) is pushing crank elements and their respective arcuate and track members. When direction of travel is reversed, the pulling and pushing of the crank elements is reversed. Referring to FIGS. 2 4, it can be seen that the major axis of the elliptical shape of track 26 remains substantially parallel to the general contour of the ground, and as objects, such as rock 64, are encountered the major axis of the elipse tilts as vehicle passes over rock 64. Thus the innerrelationship of arcuate members 40 causes the major axis to remain substantially parallel to a line which extends between the highest point and the lowest point of contact with the terrain. By virtue of the elliptical shape of track 26, and the flat surface at the bottom of track 26, the surface of contact between the terrain and track 26 is maximized and is increased considerably over the contact surface attained with most circular wheels. Furthermore, the fact that the major axis of track 26 is always maintained substantially parallel to the contour of the ground insures that the maximum surface contact is always attained.

The pivotal connections at the opposite ends of cranks 56 will often be exposed todirt and other elements, and for this reason a specially designed enclosed lubrication system has been provided to keep out the elements. Referring to FIGS. 6 8, a circular lubricant container 66 is formed around the periphery of flanges l8 by a circular plate 68 which has an angle iron shape in cross section, and which fits against the outer surface of flanges 18, 20. The effective radius of container 66 is less than the effective radius of movement of shafts 62 (FIG. 6) so that contrifugal force will cause lubricant in container 66 to move towards these shafts. Each crank element 56 includes an elongated passageway 70 which extends between its opposite ends and which is in communication with the bearing surfaces providing the rotational axes at the opposite ends of crank element 56. Lubricant container 66 includes a port 72 which provides communication between the interior of lubricant container 66 and passageway 70. Thus lubricant passes through port 72 into passageway 70 and from passageway 70 into the bearing surfaces at the opposite ends of crank element 56. Lubricant container 66 includes a plug 72 therein which may be removed to permit the filling of container 66. The lubricant within container 66 passes through passageway 70 by virtue of the centrifugal force created during the rotation of the inner wheel and crank elements 56. As the lubricant passes out of container 66 a vacuum is formed in container 66. Thus periodically plug 72 must be removed to permit the release of this vacuum so that the lubricant within container 66 will be free to flow through passageway 70. As an alternative to the periodic removal of plug 72, a pressure relief valve 74 may be provided for container 66. Valve 74 includes a valve body 76 threadably mounted in the walls of lubricant container 66. Body member 76 includes a minor cavity 78 and a filter cavity 80 which are in communication with one another through a reduced aperture 82. Threadably secured over major aperture 80 is a cap 84 and threadably secured over minor cavity 78 is another cap 86. Caps 84, 86 have apertures 88 therein so that a line of communication is provided from the exterior of lubricant container 66 to the interior of lubricant container 66. Mounted within minor cavity 78 is a ball valve 90 which is urged into aperture 82 by a spring 92. Spring 92 thus causes ball valve 90 to close off communication of air through aperture 82. However, when the vacuum within container 66 increases beyond a predetermined point, the air pressure from the atmosphere causes ball valve 90 to be yieldably moved to an open position against the bias of spring 92, thereby permitting the flow of air into lubricant container 66. Thus a valve is provided for relieving the vacuum within lubricant container 66 so that lubricant will be free to flow through passageway 70 to the bearings at the opposite ends of crank element 56.

As can be seen in FIG. 6, hinge shafts 38 are ground and polished lengths of seamless steel tubing which include radially extending bores 94 for carrying lubricant to the track bushings 32, 36, 50 and 48. The opposite ends of shafts 38 are enclosed by means of plugs 96, and lubricant is thus sealed within the interior of the tube-like hinge shafts 38. Between each bushing face FIG. 6 is an O ring or equal to seal lubricant from the atmosphere.

Thus the wheel disclosed above can be used for light or heavy wheel loads requiring more traction and more flotation on the terrain, and this wheel can be used whether the terrain is regular or rough. The wheel can be used for vehicles which require both slow and fast operating speeds and can be used for vehicles which require a short turning radius. Furthermore, it can be used for vehicles whose wheel loads are unequally distributed laterally. Because the wheel of the present invention requires only one inner wheel, it can be interchanged on vehicles presently using pneumatic tires. This can be done merely by bolting on the wheel of the present invention in place of the pneumatic wheel, or when heavy wheels are equipped with planetary drive hubs, the inner wheel rim of an elliptical wheel can be bolted to the planetary drive hub to replace the pneumatic tire and rim.

Referring to FIGS. 11 13, the numeral designates a modified form of the vehicle wheel of the present invention. Wheel 100 includes a wheel hub 102 having a vertical web 104 and an annular flange 106 extending around its outer periphery. Flange 106 includes a plurality of flat segments 108. An elongated guide 110 is mounted at each opposite end of flat segments 108 and extends across the width thereof.

An inner wheel 112 is formed by a plurality of inner wheel segments 114 which are mounted around the flat segments 108 of hub 102. Each inner wheel segment 114 includes a vertical web 1 l6 and a transverse flange 118 which forms a T-shaped cross sectional'configuration with vertical web 116 (FIG. 12). The opposite ends of transverse flanges 118 slidably extend between guides 110 on flat segments 108 of hub 102. Referring to FIG. 12, a line 120 is shown exactly perpendicular to vertical web 104 of wheel hub 102 and vertical web 116 of inner wheel 112. In FIG. 12 it can be seen that flat segments 108 of wheel hub 102 and transverse flanges 118 of inner wheel 112 are slightly out of alignment with line 120 and provide a tapered surface with reference to line 120. Thus, transverse flanges 118 provide in combination a collar-like flange which is tapered slightly from perpendicular. Flat segments 108 are tapered accordingly so as to provide mating relationship with transverse flanges 118.

The outer radial edges of inner wheel segments 114 are somewhat arcuate in shape so as to combine with one another to provide a circular outer shape for inner wheel 1 12. Rigidly mounted adjacent the outer peripheral edges of inner wheel segments 114 are a plurality of inner wheel bushings 122 (FIG. 12).

A flexible continuous track 124 is constructed of a flexible resilient materialsuch as rubber. Synthetic materials other than rubber may be used, but the preferred material must be resilient and tough. A plurality of brackets 126 are mounted to track 124 at spaced intervals around the circumference thereof. Each bracket 126 includes a horizontal elongated member 128 having a pair of ears 130 at its opposite ends. A bracket shaft 132 extends through ears 126 and through track 124 so as to pivotally mount brackets 126 to track 124 for pivotal movement about shaft 132. Brackets 126 are arranged in pairs A and B which are alternatively positioned around the periphery of track 124. A plurality of first arcuate members 134 span bracket pairs B and are connected at their opposite ends to one of the brackets in bracket pairs A. Similarly, a plurality of second arcuate members 136 span one of bracket pairs A and have their opposite ends connected to one of the brackets in bracket pairs B. Thus it can be seen that first arcuate members 134 are positioned in end-to-end relationship around the circumference of track 124, their opposite ends each being connected to one of the brackets 132 within bracket pairs A. Second arcuate members 136 are positioned in end-to-end relationship around the circumference of track 124, and each second arcuate member 136 spans one bracket pair A and is connected at its opposite ends to one of the brackets in bracket pair B. The result of this configuration is a symmetrical overlapping of first arcuate members 134 with second arcuate members 136. Between the opposite ends of each arcuate member are two bracket members 132 each of which supports one end of an arcuate member. As can be seen in FIG. 13, first arcuate members 134 are positioned slightly outwardly from second arcuate members 136 with respect to the opposite ends of brackets 126. This offsetting relationship permits the overlapping of arcuate members 134, 136. It willbe noted that vertical web 1 16 is centrally located with respect to arcuate members 134, 136 so that all the structure of track 124 and arcuate members 134, 136 is symmetrically oriented with respect to vertical web 116 of inner wheel 112.

At the approximate midpoint of each of arcuate members 134, 136 is located an arcuate member bushing 138. Pivotally mounted to each arcuate member bushing 138 by means of a shaft 140 is a crank element 142. The opposite ends of crank elements 142 are pivotally mounted to inner wheel bushings 122 by means of shafts. 144.

The general operation of wheel is very similar to the operation of wheel 10 shown in FIGS. 1 10. Inner wheel 112 and track 124 rotate in the same direction at a constant velocity while crank elements 142 rotate in the opposite direction at varying velocities, accelerating and de-accelerating as they progress around the elliptically shaped wheel. Arcuate members 134, 136 are more semicircular shaped than in the previously shown device, and are each individually connected to separate brackets rather than having their opposite ends connected in common with an adjoining arcuate member. Of particular importance is the flexibility provided by the continuous flexible or rubber track 124. As in the previously described wheel, arcuate members 134, 136 are stressed horizontally as they approach the major axis of the elliptical wheel. This horizontal stressing causes lateral forces to be exerted at the opposite ends of each arcuate member. Referring to FIG. 1 1, the spaces between each pair A and B of brackets 126 is designated by an X. These areas X are subjected to compressive forces being exerted by the arcuate members connected tov the brackets on opposite sides thereof. Because of the flexibility of tract 124 these areas deflect and thereby impart an elliptical shape to the wheel.

Thus it can be seen that the device accomplishes at least all of its stated objectives.

I claim:

1. A wheel for vehicles comprising:

a circular inner wheel adapted to be mounted on said vehicle for rotation about a horizontal axis;

a continuous flexible track surrounding said inner wheel in outward spaced relation thereto, said track comprising a plurality of pad elements joined together by a plurality of hinge means;

a plurality of supporting members each having a first end and a second end; said first end being pivotally connected to one of said hinge means and said second end being pivotally connected to another of said hinge means, said supporting members spanning at least two pad members between said first and second ends;

each of said hinge means being pivotally connected to at least one of said first ends of said supporting members whereby said supporting members overlap one another;

connecting means pivotally interconnecting said supporting members to said inner wheel,

said connecting means including a plurality of crank elements, each of said crank elements being pivotally connected to one of said supporting members for rotation about a first axis and being pivotally connected to said inner wheel for rotation about a second axis, said second axes of said crank elements being located at spaced intervals around the periphery of said inner wheel.

2. A wheel according to claim 1 wherein said wheel is approximately elliptical in shape and includes major and minor wheel axes; each one of said crank elements being movable to a position wherein its first and second axes lie on said minor wheel axis and are approximately perpendicular to the terrain; wherein a line perpendicular to said minor wheel axis and extending through said first axis of said one crank element will substantially intersect said first axes of said crank elements adjacent the opposite sides of said one crank element.

3. A wheel according to claim 2 whereby each arcuate member rotating about the second axis limits the minimum distance between adjacent first axis crank assemblies.

4. A wheel according to claim 2 wherein a line perpenciular to said minor wheel axis drawn through said one crank element's first pivotal axis is substantially parallel to a line extending through the pivotal axes formed by said hinge means at said first and second ends of the one of said supporting members to which said one crank element is connected; an intermediate hinge means being between said first and second ends of said one supporting member and being positioned a predetermined distance from said hinge means at said first and second ends of said one supporting member; said first axis of said one crank element being spaced from said first axes of said crank elements immediately adjacent thereto a distance approximately equal to said predetermined distance.

5. A wheel according to claim 4 wherein said supporting members are arranged in first and second sets, said first and second sets being arranged in pairs, said supporting members in each of said pairs having adjacent ends pivotally connected by said hinge means for rotation about a common axis; said intermediate hinge means lying on said minor wheel axis; the distance between said one crank elements first axis and said intermediate hinge means being such that said first axes of said crank elements on opposite sides of said one crank element lie on a common are having its center located at said axis formed by said intermediate hinge means, whereby said supporting members resolve said track into a near eliptical form. I

6. The wheel of claim 5 wherein the velocity of rotation of said inner wheel and said pad elements are constant in one direction and the rotation of said crank elements about the second axis are constantly rotating in the opposite direction of said hinge means and said pad elements.

7. A wheel according to claim 5 wherein the velocity of rotation of said inner wheel and the velocity of said hinge means and said pad elements are constant in one direction and the rotation of said crank elements about their second axes is constantly accelerating and deaccelerating in a direction opposite from said one direction, the acceleration and de-acceleration of said crank elements being inversely proportional to the variable distance of said hinge means and said pad elements from said horizontal rotational axis of said inner wheel as said hinge means and said pad elements move around said eliptical track.

8. A wheel according to claim 6 wherein the distance between said first and second axes of each of said crank elements is approximately equal to the distance between each of said second axes of said crank elements.

9. A wheel according to claim 8 wherein each adjoining supporting member pivot ends and pad element ends are operatively connected midway, right and left to a common hinge means.

10. A wheel according to claim 1 wherein each of said hinge means is pivotally connected to said first end of one of said supporting members and is pivotally connected to said second end of another of said supporting members; said first pivotal axes between said crank elements and said one and said other supporting members being positioned equidistant from the one of said hinge means to which said one and said other supporting members are both connected.

11. A wheel according to claim 10 wherein said first pivotal axes between said crank elements and said supporting members are located at points equidistant from said first and second ends of said supporting members.

12. The construction of a wheel according to claim 11 wherein said first and second ends of each of said supporting members are interconnected by at least two of said pad elements, the relative width of said pad elements and said supporting members being such that said arcuate members are substantially free from horiz92 lt5ssxh9 y aid o naqcl memsfq m n angle of degrees with respect to one another, whereby said supporting members will be horizontally stressed when said track is in an elliptical shape thereby causing said track to maintain a substantially elliptical shape.

13. A wheel according to claim 1 wherein said crank elements are each rotatably journaled in a pair of bearings for rotation at said first and second axes; a lubricant container being adjacent one of said first and second axes; each of said crank elements having a passageway therein extending between and being in communication with said bearings; said lubricant container having a port therein in communication with said passageway whereby lubricant will pass from said container through said port and said passageway to said bearings.

14. A wheel according to claim 13 wherein said container includes an opening therein forming communication from the interior thereof to the atmosphere, a valve member being in said opening and being movable from a closed position wherein it closes off the interior of said container from the atmosphere to an open position wherein the interior of said container is exposed to the atmosphere.

15. A wheel according to claim 14 wherein a spring engages said valve member and yieldably holds said valve member in its closed position, said valve member being yieldably movable to its open position against the bias of said spring member in response to a predetermined difference in air pressure between the interior and exterior of said container.

16. In a tractor wheel for vehicles having a hub operatively secured to a source of rotational power,

a flexible continuous track comprised of a plurality of pivotally interconnected pad elements;

a first set of normally rigid supporting legs of fixed configuration having opposite ends pivotally connected adjacent the edges of two of said pad elements, each of said supporting legs in said first set spanning at least two of said pad elements and the pivotal connections therebetween;

a second set of normally rigid supporting legs of fixed configuration overlapping said first set of supporting legs and having opposite ends pivotally connected adjacent said-pivotal connection and being spanned by each of said leg elements of said first set; and

a plurality of crank elements each being pivotally secured to one of said supporting legs for swinging movement about a first axis and each being adapted to be secured to said hub for swinging movement about a second axis.

17. A tractor wheel according to claim 16 wherein said first and second sets of supporting legs are arranged in pairs, said arcuate members in each of said pairs having adjacent ends pivotally connected to said pad elements for rotation about a common axis; the relative sizes of said supporting legs, said crank elements and said pad elements being such that said pivotal axes between said crank elements and said pair of supporting legs lie on a common arc having its center located at said common axis between said pair of supporting legs.

18. A tractor wheel according to claim 16 wherein said supporting legs and said crank elements hold said pad elements in continuous spaced relation to said hub.

19. A wheel for vehicles comprising:

a circular inner wheel adapted to be mounted on said vehicle for rotation about a horizontal axis; continuous flexible track surrounding said inner wheel in outward spaced relation thereto, said track comprising a plurality of pad elements joined together by a plurality of hinge means;

plurality of normally rigid supporting members of fixed configuration each having a first end and a second end; said first end being pivotally connected to one of said hinge means and said second' end being pivotally connected to another of said hinge means, said supporting members spanning at least two pad members between said first and sec-' ond ends;

each of said hinge means being pivotally connected to at least one of said first ends of said supporting members whereby said supporting members overlap one another; and

connecting means pivotally interconnecting said supporting members to said inner wheel.

20. The wheel according to claim 19 wherein said supporting members and said connecting means hold said pad members in continuous spaced relation to said inner wheel.

21. A wheel for vehicles comprising:

a circular inner wheel adapted to be mounted on said said second end of said sup-porting member diverging into two legs which are connected at opposite sides of the longitudinal midpoint of another of said hinge means;

each of said supporting members spanning at least two adjoining pad elements;

each of said hinge means being connected to said first end of one of said supporting members and to said second end of another of said supporting members whereby said supporting members overlap one another; and

connecting means pivotally interconnecting said supporting members to said inner wheel.

22. The wheel according to claim 21 wherein said supporting members and said connecting means hold said pad elements in continuous spaced relation to said inner wheel.

23. A vehicle wheel comprising:

a continuous flexible track;

a plurality of brackets pivotally mounted on said track, said brackets being arranged in first and second pairs which are alternatively positioned around the circumference of said track;

a plurality of normally rigid first supporting members of fixed configuration each having a first end connected to one of said brackets in one of said first pairs and each having a second and end connected to one of said brackets in another of said first pairs, said first supporting members spanning at least one of said second pairs of said brackets;

a plurality of normally rigid second supporting members of fixed configuration each having a first end connected to one of said brackets in one of said second pairs and each having a second end connected to one of said brackets in another of said second pairs said second sup-porting members each spanning at least one of said first pairs of said brackets;

a inner wheel adapted to be operatively connected to a wheel hub; and

connecting means pivotally interconnecting each of said first and second supporting members to said inner wheel.

24. A wheel according to claim 23 wherein said supporting members and connecting means hold said brackets in continuous spaced relation to said inner wheel.

25. A wheel according to claim 23 wherein said track is comprised of a flexible material which will stretch and contract in response to compression and tension being exerted between said brackets.

26. In a tractor wheel for vehicles having a hub operatively secured to a source of rotational power,

a flexible continuous track comprised of a plurality of pivotally interconnected, pad elements;

a first set of supporting legs having opposite ends pivotally connected adjacent the edges of two of said pad elements, each of said supporting legs in said first set spanning at least two of said pad elements and the pivotal connections therebetween;

a second set of supporting legs overlapping said first set of supporting legs and having opposite ends pivotally connected adjacent said pivotal connection and being spanned by each of said leg elements of said first set; and

a plurality of crank elements each being pivotally secured to one of said supporting legs for swinging movement about a first axis and each being adapted to be secured to said hub for swinging movement about a second axis;

said first and second sets of supporting legs being arranged in pairs, said supporting legs in each of said pairs having adjacent ends pivotally connected to said pad elements for rotation about a common axis; the relative sizes of said supporting legs, said crank elements and said pad elements being such that said pivotal axes between said crank elements and said pair of supporting legs lie on a common are having its center located at said common axis between said pair of supporting legs.

27. A wheel for vehicles comprising,

a circular inner wheel adapted to be mounted on said vehicle for rotation about a horizontal axis;

a continuous flexible track surrounding said inner wheel in outward spaced relation thereto, said track comprising a plurality of pad elements;

a plurality of supporting members each having a first end and a second end; each of said supporting members being secured to at least one of said pad elements and spanning portions of at least two pad members between said first and second ends;

connecting means pivotally interconnecting said supporting members to said innerwheel,

said connecting means including a plurality of crank elements, each of said crank elements being pivotally connected to one of said supporting members for rotation about a first axis and being pivotally con-nected to said inner wheel for rotation about a second axis, said second axes of said crank elements being located at spaced intervals about the periphery of said inner wheel; whereby each supporting member rotating about the second axis limits the minimum dis-tance between the first axis of said crank assemblies.

28. A wheel according to claim 27 wherein the velocity of rotation of said inner wheel and the velocity of said pad elements are constant in one direction and the rotation of said crank elements about their second axes is constantly accelerating and de-accelerating in a direction opposite from said one direction, the acceleration and the de-acceleration of said crank elements being inversely proportional to the variable distance of said pad elements from said horizontal rotational axis of said inner wheel as said pad elements move around the periphery of said wheel.

29. A wheel for vehicles comprising,

a circular inner wheel adapted to be mounted on said vehicle for rotation about a horizontal axis;

a continuous flexible track surrounding said inner wheel in outward spaced relation thereto, said track comprising a plurality of interconnected pad members a plurality of normally rigid supporting members of fixed configuration each having a first end and a second end; each of said supporting members being secured to at least one of said pad members and spanning portions of at least two pad members between said first and second ends;

and connecting means pivotally interconnecting said supporting members to said inner wheel,; said supporting members and said connecting means holding said pad members in continuous spaced relation to said inner wheel.

30. A vehicle wheel comprising:

a continuous flexible track;

a plurality of brackets pivotally mounted to said track, said brackets being arranged in first and second pairs which re alternatively posi-tioned around the circumference of said track;

a plurality of first supporting members each having a first end connected to one of said brackets in one of said first pairs and each having a second end connected to one of said brackets in another of said first pairs, said first supporting members spanning at least one of said second pairs of said brackets;

a plurality of second supporting members each having a first end connected to one of said brackets in one of said second pairs and each having a second end connected to one of said brackets in another of said second pairs, said second supporting members each spanning at least one of said first pairs of said brackets;

an inner wheel adapted to be operatively connected to a wheel hub;

connecting means pivotally interconnecting each of said first and second supporting members to said inner wheel;

said connecting means including a plurality of crank elements each pivotally connected to said inner wheel and to one of said first and second supporting members.

31. A wheel according to claim 30 wherein said bracket members are elongated and extend across the width of said flexible track; each of said brackets having one of said supporting members connected thereto adjacent each of the opposite ends of said bracket, said first supporting members being positioned slightly inwardly from said second supporting members with respect to the opposite ends of said brackets so as to permit overlapping of said first and second supporting members.

32. A wheel according to claim 30 wherein said inner wheel includes an annular vertical flange extending around its circumference, said crank elements being connected to said vertical flange.

33. A wheel according to claim 32 wherein said annular vertical flange is formed by a plurality of inner wheel segments having T-shaped cross sec-tional configuration, said vertical flange being the upstanding portion of said T-shape and the cross bar of said T- shape being presented radially inwardly and adapted to be secured to a hub.

34. A wheel according to claim 22 wherein said cross bar of each of said wheel segments is slightly offset from perpendicular with respect to said vertical flanges so as to create a tapered annular collar on the inner radial portion of said inner wheel for engaging an annular flange on said hub.

35. A wheel according to claim 33 wherein said crossbars of each of said segments is slightly offset from the perpendicular with respect to said vertical flanges so as to create a matching tapered annular collar on the inner radial portion of said inner wheel for expanding the radial diameter of said second axis of each of said crank elements at the time of assembly.

i ll l l 

1. A wheel for vehicles comprising: a circular inner wheel adapted to be mounted on said vehicle for rotation about a horizontal axis; a continuous flexible track surrounding said inner wheel in outward spaced relation thereto, said track comprising a plurality of pad elements joined together by a plurality of hinge means; a plurality of supporting members each having a first end and a second end; said first end being pivotally connected to one of said hinge means and said second end being pivotally connected to another of said hinge means, said supporting members spanning at least two pad members between said first and second ends; each of said hinge means being pivotally connected to at least one of said first ends of said supporting members whereby said supporting members overlap one another; connecting means pivotally interconnecting said supporting members to said inner wheel, said connecting means including a plurality of crank elements, each of said crank elements being pivotally connected to one of said supporting members for rotation about a first axis and being pivotally connected to said inner wheel for rotation about a second axis, said second axes of said crank elements being located at spaced intervals around the periphery of said inner wheel.
 2. A wheel according to claim 1 wherein said wheel is approximately elliptical in shape and includes major and minor wheel axes; each one of said crank elements being movable to a position wherein its first and second axes lie on said minor wheel axis and are approximately perpendicular to the terrain; wherein a line perpendicular to said minor wheel axis and extending through said first axis of said one crank element will substantially intersect said first axes of said crank elements adjacent the opposite sides of said one crank element.
 3. A wheel according to claim 2 whereby each arcuate member rotating about the second axis limits the minimum distance between adjacent first axis crank assemblies.
 4. A wheel according to claim 2 wherein a line perpenciular to said minor wheel axis drawn through said one crank element''s first pivotal axis is substantially parallel to a line extending through the pivotal axes formed by said hinge means at said first and second ends of the one of said supporting members to which said one crank element is connected; an intermediate hinge means being between said first and second ends of said one supporting member and being positioned a predetermined distance from said hinge means at said first and second ends of said one supporting member; said first axis of said one crank element being spaced from said first axes of said crank elements immediately adjacent thereto a distance approximately equal to said predetermined distance.
 5. A wheel according to claim 4 wherein said supporting members are arranged in first and second sets, said first and second sets being arranged in pairs, said supporting members in each of said pairs having adjacent ends pivotally connected by said hinge means for rotation about a common axis; said intermediate hinge means lying on said minor wheel axis; the distance between said one crank element''s first axis and said intermediate hinge means being such that said first axes of said crank elements on opposite sides of said one crank element lie on a common arc having its center located at said axis formed by said intermediate hinge means, whereby said supporting members resolve said track into a near eliptical form.
 6. The wheel of claim 5 wherein the velocity of rotation of said inner wheel and said pad elements are constant in one direction and the rotation of said crank elements about the second axis are constantly rotating in the opposite direction of said hinge means and said pad elements.
 7. A wheel according to claim 5 wherein the velocity of rotation of said inner wheel and the velocity of said hinge means and said pad elements are constant in one direction and the rotation of said crank elements about their second axes is constantly accelerating and de-accelerating in a direction opposite from said one direction, the acceleration and de-acceleration of said crank elements being inversely proportional to the variable distance of said hinge means and said pad elements from said horizontal rotational axis of said inner wheel as said hinge means and said pad elements move around said eliptical track.
 8. A wheel according to claim 6 wherein the distance between said first and second axes of each of said crank elements is approximately equal to the distance between each of said second axes of said crank elements.
 9. A wheel according to claim 8 wherein each adjoining supporting member pivot ends and pad element ends are operatively connected midway, right and left to a common hinge means.
 10. A wheel according to claim 1 wherein each of said hinge means is pivotally connected to said first end of one of said supporting members and is pivotally connected to said second end of another of said supporting members; said first pivotal axes between said crank elements and said one and said other supporting members being positioned equidistant from the one of said hinge means to which said one and said other supporting members are both connected.
 11. A wheel according to claim 10 wherein said first pivotal axes between said crank elements and said sUpporting members are located at points equidistant from said first and second ends of said supporting members.
 12. The construction of a wheel according to claim 11 wherein said first and second ends of each of said supporting members are interconnected by at least two of said pad elements, the relative width of said pad elements and said supporting members being such that said arcuate members are substantially free from horizontal stress whenever said two pad elements form an angle of 180 degrees with respect to one another, whereby said supporting members will be horizontally stressed when said track is in an elliptical shape thereby causing said track to maintain a substantially elliptical shape.
 13. A wheel according to claim 1 wherein said crank elements are each rotatably journaled in a pair of bearings for rotation at said first and second axes; a lubricant container being adjacent one of said first and second axes; each of said crank elements having a passageway therein extending between and being in communication with said bearings; said lubricant container having a port therein in communication with said passageway whereby lubricant will pass from said container through said port and said passageway to said bearings.
 14. A wheel according to claim 13 wherein said container includes an opening therein forming communication from the interior thereof to the atmosphere, a valve member being in said opening and being movable from a closed position wherein it closes off the interior of said container from the atmosphere to an open position wherein the interior of said container is exposed to the atmosphere.
 15. A wheel according to claim 14 wherein a spring engages said valve member and yieldably holds said valve member in its closed position, said valve member being yieldably movable to its open position against the bias of said spring member in response to a predetermined difference in air pressure between the interior and exterior of said container.
 16. In a tractor wheel for vehicles having a hub operatively secured to a source of rotational power, a flexible continuous track comprised of a plurality of pivotally interconnected pad elements; a first set of normally rigid supporting legs of fixed configuration having opposite ends pivotally connected adjacent the edges of two of said pad elements, each of said supporting legs in said first set spanning at least two of said pad elements and the pivotal connections therebetween; a second set of normally rigid supporting legs of fixed configuration overlapping said first set of supporting legs and having opposite ends pivotally connected adjacent said pivotal connection and being spanned by each of said leg elements of said first set; and a plurality of crank elements each being pivotally secured to one of said supporting legs for swinging movement about a first axis and each being adapted to be secured to said hub for swinging movement about a second axis.
 17. A tractor wheel according to claim 16 wherein said first and second sets of supporting legs are arranged in pairs, said arcuate members in each of said pairs having adjacent ends pivotally connected to said pad elements for rotation about a common axis; the relative sizes of said supporting legs, said crank elements and said pad elements being such that said pivotal axes between said crank elements and said pair of supporting legs lie on a common arc having its center located at said common axis between said pair of supporting legs.
 18. A tractor wheel according to claim 16 wherein said supporting legs and said crank elements hold said pad elements in continuous spaced relation to said hub.
 19. A wheel for vehicles comprising: a circular inner wheel adapted to be mounted on said vehicle for rotation about a horizontal axis; a continuous flexible track surrounding said inner wheel in outward spaced relation thereto, said track comprising a plurality of pad elements joined together by a plurality of hinge means; a plurality of normally rigid supporting members of fixed configuration each having a first end and a second end; said first end being pivotally connected to one of said hinge means and said second end being pivotally connected to another of said hinge means, said supporting members spanning at least two pad members between said first and second ends; each of said hinge means being pivotally connected to at least one of said first ends of said supporting members whereby said supporting members overlap one another; and connecting means pivotally interconnecting said supporting members to said inner wheel.
 20. The wheel according to claim 19 wherein said supporting members and said connecting means hold said pad members in continuous spaced relation to said inner wheel.
 21. A wheel for vehicles comprising: a circular inner wheel adapted to be mounted on said vehicle for rotation about a horizontal axis; a continuous flexible track surrounding said inner wheel in outward spaced relation thereto, said track comprising a plurality of pad elements joined together by a plurality of hinge means; a plurality of normally rigid supporting members of fixed configuration each having a first end and a second end; said hinge means being elongated, said first end being pivotally connected approximately midway of the length of one of said hinge means, said second end of said sup-porting member diverging into two legs which are connected at opposite sides of the longitudinal midpoint of another of said hinge means; each of said supporting members spanning at least two adjoining pad elements; each of said hinge means being connected to said first end of one of said supporting members and to said second end of another of said supporting members whereby said supporting members overlap one another; and connecting means pivotally interconnecting said supporting members to said inner wheel.
 22. The wheel according to claim 21 wherein said supporting members and said connecting means hold said pad elements in continuous spaced relation to said inner wheel.
 23. A vehicle wheel comprising: a continuous flexible track; a plurality of brackets pivotally mounted on said track, said brackets being arranged in first and second pairs which are alternatively positioned around the circumference of said track; a plurality of normally rigid first supporting members of fixed configuration each having a first end connected to one of said brackets in one of said first pairs and each having a second and end connected to one of said brackets in another of said first pairs, said first supporting members spanning at least one of said second pairs of said brackets; a plurality of normally rigid second supporting members of fixed configuration each having a first end connected to one of said brackets in one of said second pairs and each having a second end connected to one of said brackets in another of said second pairs said second sup-porting members each spanning at least one of said first pairs of said brackets; a inner wheel adapted to be operatively connected to a wheel hub; and connecting means pivotally interconnecting each of said first and second supporting members to said inner wheel.
 24. A wheel according to claim 23 wherein said supporting members and connecting means hold said brackets in continuous spaced relation to said inner wheel.
 25. A wheel according to claim 23 wherein said track is comprised of a flexible material which will stretch and contract in response to compression and tension being exerted between said brackets.
 26. In a tractor wheel for vehicles having a hub operatively secured to a source of rotational power, a flexible continuous track comprised of a plurality of pivotally interconnected, pad elements; a first set of supporting legs having opposite ends pivotally connected adjacent the edges of two of said pad elements, each of said supporting legs in said first set spanning at lEast two of said pad elements and the pivotal connections therebetween; a second set of supporting legs overlapping said first set of supporting legs and having opposite ends pivotally connected adjacent said pivotal connection and being spanned by each of said leg elements of said first set; and a plurality of crank elements each being pivotally secured to one of said supporting legs for swinging movement about a first axis and each being adapted to be secured to said hub for swinging movement about a second axis; said first and second sets of supporting legs being arranged in pairs, said supporting legs in each of said pairs having adjacent ends pivotally connected to said pad elements for rotation about a common axis; the relative sizes of said supporting legs, said crank elements and said pad elements being such that said pivotal axes between said crank elements and said pair of supporting legs lie on a common arc having its center located at said common axis between said pair of supporting legs.
 27. A wheel for vehicles comprising, a circular inner wheel adapted to be mounted on said vehicle for rotation about a horizontal axis; a continuous flexible track surrounding said inner wheel in outward spaced relation thereto, said track comprising a plurality of pad elements; a plurality of supporting members each having a first end and a second end; each of said supporting members being secured to at least one of said pad elements and spanning portions of at least two pad members between said first and second ends; connecting means pivotally interconnecting said supporting members to said innerwheel, said connecting means including a plurality of crank elements, each of said crank elements being pivotally connected to one of said supporting members for rotation about a first axis and being pivotally con-nected to said inner wheel for rotation about a second axis, said second axes of said crank elements being located at spaced intervals about the periphery of said inner wheel; whereby each supporting member rotating about the second axis limits the minimum dis-tance between the first axis of said crank assemblies.
 28. A wheel according to claim 27 wherein the velocity of rotation of said inner wheel and the velocity of said pad elements are constant in one direction and the rotation of said crank elements about their second axes is constantly accelerating and de-accelerating in a direction opposite from said one direction, the acceleration and the de-acceleration of said crank elements being inversely proportional to the variable distance of said pad elements from said horizontal rotational axis of said inner wheel as said pad elements move around the periphery of said wheel.
 29. A wheel for vehicles comprising, a circular inner wheel adapted to be mounted on said vehicle for rotation about a horizontal axis; a continuous flexible track surrounding said inner wheel in outward spaced relation thereto, said track comprising a plurality of interconnected pad members a plurality of normally rigid supporting members of fixed configuration each having a first end and a second end; each of said supporting members being secured to at least one of said pad members and spanning portions of at least two pad members between said first and second ends; and connecting means pivotally interconnecting said supporting members to said inner wheel,; said supporting members and said connecting means holding said pad members in continuous spaced relation to said inner wheel.
 30. A vehicle wheel comprising: a continuous flexible track; a plurality of brackets pivotally mounted to said track, said brackets being arranged in first and second pairs which re alternatively posi-tioned around the circumference of said track; a plurality of first supporting members each having a first end connected to one of said brackets in one of said first pairs and each having a second end connected to one of said brackets in another of sAid first pairs, said first supporting members spanning at least one of said second pairs of said brackets; a plurality of second supporting members each having a first end connected to one of said brackets in one of said second pairs and each having a second end connected to one of said brackets in another of said second pairs, said second supporting members each spanning at least one of said first pairs of said brackets; an inner wheel adapted to be operatively connected to a wheel hub; connecting means pivotally interconnecting each of said first and second supporting members to said inner wheel; said connecting means including a plurality of crank elements each pivotally connected to said inner wheel and to one of said first and second supporting members.
 31. A wheel according to claim 30 wherein said bracket members are elongated and extend across the width of said flexible track; each of said brackets having one of said supporting members connected thereto adjacent each of the opposite ends of said bracket, said first supporting members being positioned slightly inwardly from said second supporting members with respect to the opposite ends of said brackets so as to permit overlapping of said first and second supporting members.
 32. A wheel according to claim 30 wherein said inner wheel includes an annular vertical flange extending around its circumference, said crank clements being connected to said vertical flange.
 33. A wheel according to claim 32 wherein said annular vertical flange is formed by a plurality of inner wheel segments having T-shaped cross sec-tional configuration, said vertical flange being the upstanding portion of said T-shape and the cross bar of said T-shape being presented radially inwardly and adapted to be secured to a hub.
 34. A wheel according to claim 22 wherein said cross bar of each of said wheel segments is slightly offset from perpendicular with respect to said vertical flanges so as to create a tapered annular collar on the inner radial portion of said inner wheel for engaging an annular flange on said hub.
 35. A wheel according to claim 33 wherein said crossbars of each of said segments is slightly offset from the perpendicular with respect to said vertical flanges so as to create a matching tapered annular collar on the inner radial portion of said inner wheel for expanding the radial diameter of said second axis of each of said crank elements at the time of assembly. 